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Bioactive glasses (BG) are known for their ability to bond to hard and soft tissues. We hypothesized that the stimulation of bone remodeling, including cellular bone forming and bone resorbing processes, can be increased by applying periodic microstructures on the glass surfaces in vitro. To test our hypothesis, two different BG (45S5 and 13-93) were microstructured in a groove-and-ridge pattern of different sizes by a novel casting process and tested in cell culture experiments using human mesenchymal stromal cells (hMSCs) and RAW 264.7 cells. The microstructures induced contact guidance of hMSCs and increased osteogenic marker gene expression of the stem cells, compared to non-structured glass surfaces as verified by ELISA and quantitative real-time PCR (qPCR) analyses. Furthermore, the structures stimulated the differentiation of RAW cells to osteoclast-like cells confirmed by TRAP gene expression and their resorption activity causing visible resorption lacunae. Our results demonstrate that periodically microstructured BG (especially 45S5) might improve the osteogenic differentiation of hMSCs and influence the activity of material resorbing cells in vitro. Hence, microstructuring of BG could enhance the remodeling process of bone substitutes critical for the formation of new bone tissue in vivo and thus be used to trigger bone remodeling kinetics in vivo. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1965-1978, 2018., (© 2018 Wiley Periodicals, Inc.)

Progress in material development has enabled the production of nerve guides that increasingly resemble the characteristics of an autologous nerve graft. In the present study, 20 mm adult rat sciatic nerve defects were bridged with the collagen-based, two-component nerve guide 'Neuromaix', the commercially available NeuraGen® nerve tube or an autologous nerve graft. Neuromaix was able to support structural as well as functional regeneration across this gap. The majority of the axons grew across the scaffold into the distal nerve segment and retrograde tracing confirmed that these axons were of somatosensory and motor origin. Histomorphology revealed that axons regenerating through Neuromaix exhibited reduced myelin sheath thickness, whereas axon diameter and axon density were comparable to those of the autograft. Neuromaix implantation resulted in reinnervation of the gastrocnemius muscle to a level that was not significantly different from that supported by the autograft, as demonstrated by electrophysiology. Our findings show that the use of the Neuromaix scaffold not only allowed axonal regeneration across large nerve gaps, but that the regenerating axons were also able to functionally reinnervate the muscles. These data provide a promising perspective for the first in human application of the materials. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

The present investigation deals with the development of a pH and time-dependent press-coated pulsatile drug delivery system for delivering drugs into the colon. The system consists of a drug containing core, coated by a combination of natural polymer Delonix regia gum (DRG) and hydroxypropyl methylcellulose (HPMC K4M) in various proportions, which controls the onset of release. The whole system was coated with methacrylic acid copolymers, which not only prevents the drug release in the stomach, but also prolongs the lag time. Tramadol HCl was used as a model drug and varying combinations of DRG and HPMC K4M were used to achieve the desired lag time before rapid and complete release of the drug in the colon. It was observed that the lag time depends on the coating ratio of DRG to HPMC and also on press coating weight. Drug release was found to be increased by 15-30% in the presence of colonic microbial flora. The results showed the capability of the system in achieving pulsatile release for a programmable period of time and pH-dependent release to attain colon-targeted delivery.